The invention concerns a disc wheel cover in an automobile. A disc wheel cover is used for adornment covering the disc wheel, and a conventional disc wheel cover 10 has the structure shown in FIG. 1, comprising a base plate 11, six or eight hook arms 12 each having a hook 121 for catching and holding a disc wheel side ring 13, which serves for urging outward the hook arms 12 with the tightening force caused by hooks arms 12 when they stick in the inner circumferential edge of a disc wheel.
Said disc wheel side ring 13 has the structure shown in FIG. 2, and is made of a slender round bar having both ends welded together so that it has definite diameter impossible to be varied a bit, thus the functional diameter formed by the outer edges of the hook arms 12 is also difinite or unadjustable, as shown in FIG. 2, after engaging the disc wheel side ring 13 to the hooks 121.
As the disc wheel cover rotates very fast synchroneously together with the wheel, the interconnecting tightness between the hook arms 12 and the inner circumferential edge of the disc wheel is extremely important. If their mutual tightness is not proper, the disc wheel cover may accidentally fall off and wound a person walking on the street during driving of a car.
When the inner circumferential edge of a disc wheel has a diameter a little different from the definite functional diameter that the hook arms 12 define, the disc wheel cover 10 may not be fixed with the disc wheel in a secured condition. Though a disc wheel theoretically has a certain inner diameter, it is inevitable that some error may happen in the manufacturing process. Some disc wheel covers are easily fixed with a disc wheel or even may slightly be loose, and it means that the inner circumferential edge of the disc wheel has a little larger diameter than the functional diameter the disc wheel cover 10 has, and the disc wheel cover is unsuable. On the contrary, if a disc wheel cover 10 is difficult to be fixed to a disc wheel or cannot be fixed thereto without hammer, it means that the inner circumferential edge of the disc wheel has a smaller diameter than the functional diameter the disc wheel cover 10 has. The cause of these two cases originates from the error of the outer diameter the disc wheel has and the definite, unadjustable diameter the disc wheel cover side ring has.
This invention aims to furnish a disc wheel side ring of which the diameter is adjustable between two different measurements so as to cope with the diametrical error a disc wheel may have.